KEY: S = Estimate does not meet publication standards because of high sampling variability or poor response quality. - = Zero or Less than half the unit shown; thus, it has been rounded to zero.

1 Commodity Flow Survey (CFS) geographic areas were drawn from a subset of Combined Statistical Areas (CSAs) and Metropolitan Statistical Areas (MeSAs) as defined by the Office of Management and Budget (OMB). However, CFS metropolitan areas are divided into their state parts when they include more than one state. In addition, the CFS also utilizes a unique geography referred to as, "remainder of state," to represent those areas of a state not contained within a separately published metropolitan area for the CFS (as opposed to not part of any Core-Based Statistical Area (CBSA) as defined by OMB). Because of the differences in the CFS geography, as compared to OMB defined geography, caution should be exercised when comparing CFS estimates to other estimates of similar geography.2 North American Industry Classification System3 Ton-miles estimates are based on estimated distances traveled along a modeled transportation network.4 Coefficient of Variation.

NOTES: Value-of-shipment estimates are reported in current prices. Estimated measures of sampling variability for each estimate known as coefficients of variation (CV) are also provided in these tables. More information on sampling error, confidentiality protection, nonsampling error, sample design, and definitions may be found at http://www.bts.gov/publications/commodity_flow_survey/.
Industries are not shown if there is no data for a particular industry. For example, since Washington-Arlington-Alexandria, DC-VA-MD-WV (DC part) by Mining (except oil and gas) (NAICS 212) has no data for any shipment weight group, the entire industry for that area was removed from this table. However, if an industry has at least one row of data for one of the shipment weight groups, then the entire industry is shown for that area even though there may be shipment weight groups absent of data within that industry. For example, Washington-Arlington-Alexandria, DC-VA-MD-WV (DC part) by Hardware and plumbing merchant wholesalers (NAICS 4237) has the majority of rows absent of data but does have data for the "Less than 50 lbs" shipment weight group so that industry will be shown in its entirety.

SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 2007 Economic Census: Transportation Commodity Flow Survey, December 2009.